From a subset of healthy adult subjects (up to 30 volunteers 18-64 years old enrolled at the Emory VTEU site who consent to blood donation for the immunology exploratory assays), an additional volume of venous blood will be drawn on Days 0, 8, 21, 29 and 42 to determine the specificity/cross reactivity of antibodies from H3N2v-reactive B cells with other influenza subtypes (e.g., 2009 H1N1 pandemic HA) and most recent H3 seasonal HA to define the molecular profile of antibody repertoire changes in circulating B cells after H3N2v vaccination, and to characterize the antibody-secreting cell (ASC), monoclonal antibody (mAb), and CD4+ T cell responses to H3N2v vaccination. The duration of the study for each subject will be approximately 7 months. Parent protocol to sub-study 12-0089 and 12-0015.